Maybe the Jacksons just didn't see it.
Example: Mormonism was blatantly racist with the priesthood until it threatened their tax-exempt status - Brigham Young made the Klan look tolerant - but they were still willing to take black people as converts.
And tell them they could be servants in the heavenly kingdom. I sh*t you not. But some converted anyway.
So the Jacksons don't really prove anything.